People living with HIV (PLWHs) who inject heroin or other opioids are substantially less likely to engage or be retained in HIV care and less likely to achieve virologic suppression. They also have faster rates of HIV viral progression and higher mortality compared to PLWHs who dont inject drugs. Long-acting formulations of medications for opioid-use disorder present an opportunity to increase patients engagement into the HIV care continuum. A recently developed formulation of buprenorphine provides a continuous window of withdrawal suppression and opioid blockade. This may lead to a cycle of stable behavior on multiple fronts, including greater adherence to antiretroviral therapy (ART), greater attendance to appointments for HIV clinical care, more consistent avoidance of transmission-risk behaviors, and more steadily maintained suppression of viral load. In this pilot study, up to 60 PLWHs in HIV treatment who are also seeking treatment for opioid-use disorder will be randomized to subcutaneous long-acting buprenorphine injections or treatment as usual (e.g., referral to standard office-based buprenorphine treatment) while ART is continued. Over 12 months, we will monitor HIV-1 RNA levels, CD4 lymphocyte count, ART adherence, retention in HIV care, and avoidance of transmission-risk behaviors. We hypothesize that long-acting buprenorphine, compared to treatment as usual, will improve engagement into the HIV care continuum, specifically in stability of viral suppression. We have been working with the manufacturer of a long-acting subcutaneous formulation of buprenorphine to obtain materials for initiation of a collaborative trial.